ghosts can no longer duplicate themselves in the mob subsystem list tracking them

code/controllers/subsystem/mobs.dm

@@ -40,5 +40,6 @@ SUBSYSTEM_DEF(mobs)
 			L.Life(seconds, times_fired)
 		else
 			GLOB.mob_living_list.Remove(L)
+			stack_trace("[L] no longer exists in mob_living_list")
 		if (MC_TICK_CHECK)
 			return

code/game/atoms_movable.dm

@@ -540,7 +540,7 @@
 
 	var/previous_virtual_z = OldLoc?.virtual_z() || 0
 	var/current_virtual_z = virtual_z()
-	if(current_virtual_z && current_virtual_z != previous_virtual_z)
+	if(current_virtual_z != previous_virtual_z)
 		on_virtual_z_change(current_virtual_z, previous_virtual_z)
 
 	SEND_SIGNAL(src, COMSIG_MOVABLE_MOVED, OldLoc, Dir, Forced, old_locs)

code/game/machinery/navbeacon.dm

@@ -46,11 +46,15 @@
 	return ..()
 
 /obj/machinery/navbeacon/on_virtual_z_change(new_virtual_z, previous_virtual_z)
+	..()
+	if(!codes)
+		return
+	if(!codes["patrol"])
+		return
 	if(previous_virtual_z)
 		LAZYREMOVEASSOC(GLOB.navbeacons, "[previous_virtual_z]", src)
 	if(new_virtual_z)
 		LAZYADDASSOCLIST(GLOB.navbeacons, "[new_virtual_z]", src)
-	..()
 
 // set the transponder codes assoc list from codes_txt
 /obj/machinery/navbeacon/proc/set_codes()
@@ -71,7 +75,10 @@
 			codes[e] = "1"
 
 /obj/machinery/navbeacon/proc/glob_lists_deregister()
-	LAZYREMOVE(GLOB.navbeacons["[virtual_z()]"], src)
+	if(!codes)
+		return
+	if(codes["patrol"])
+		LAZYREMOVE(GLOB.navbeacons["[virtual_z()]"], src)
 	GLOB.deliverybeacons -= src
 	GLOB.deliverybeacontags -= location
 	GLOB.wayfindingbeacons -= src

code/modules/mob/dead/dead.dm

@@ -96,18 +96,17 @@ INITIALIZE_IMMEDIATE(/mob/dead)
 	return
 
 /mob/dead/Destroy()
-	for(var/level in SSmobs.dead_players_by_virtual_z)
-		LAZYREMOVEASSOC(SSmobs.dead_players_by_virtual_z, level, src)
-	// Forgive me for this one. This loop can be replaced by the line below by the one brave enough to fix
-	// observers not cleanly removing themselves from the dead_players_by_virtual_z /list when they should
-	//LAZYREMOVEASSOC(SSmobs.dead_players_by_virtual_z, "[virtual_z()]", src)
+	//Observers should no longer be duplicating themselves across virtual z so it SHOULD be fine to only check its virtual z.
+	LAZYREMOVEASSOC(SSmobs.dead_players_by_virtual_z, "[virtual_z()]", src)
 	return ..()
 
 /mob/dead/Login()
 	. = ..()
 	if(!client)
 		return
-	LAZYADDASSOCLIST(SSmobs.dead_players_by_virtual_z, "[virtual_z()]", src)
+	var/virt_z = virtual_z()
+	if(virt_z)
+		LAZYADDASSOCLIST(SSmobs.dead_players_by_virtual_z, "[virt_z]", src)
 
 /mob/dead/Logout()
 	. = ..()

code/modules/mob/living/login.dm

@@ -18,8 +18,9 @@
 
 
 	var/virtual_z = virtual_z()
-	LAZYADDASSOCLIST(SSmobs.players_by_virtual_z, "[virtual_z]", src)
-	SSidlenpcpool.try_wakeup_virtual_z(virtual_z)
+	if(virtual_z)
+		LAZYADDASSOCLIST(SSmobs.players_by_virtual_z, "[virtual_z]", src)
+		SSidlenpcpool.try_wakeup_virtual_z(virtual_z)
 
 	//Vents
 	if(ventcrawler)

code/modules/mob/living/simple_animal/simple_animal.dm

@@ -630,30 +630,29 @@
 	GLOB.simple_animals[togglestatus] += list(src)
 	AIStatus = togglestatus
 
-	var/virt_z = "[virtual_z()]"
+	var/virt_z = virtual_z()
 	if(!virt_z)
 		return
 
 	switch(togglestatus)
 		if(AI_Z_OFF)
-			LAZYADDASSOCLIST(SSidlenpcpool.idle_mobs_by_virtual_level, virt_z, src)
-
+			LAZYADDASSOCLIST(SSidlenpcpool.idle_mobs_by_virtual_level, "[virt_z]", src)
 		else
-			LAZYREMOVEASSOC(SSidlenpcpool.idle_mobs_by_virtual_level, virt_z, src)
+			LAZYREMOVEASSOC(SSidlenpcpool.idle_mobs_by_virtual_level, "[virt_z]", src)
 
 /mob/living/simple_animal/proc/check_should_sleep()
 	if (pulledby || shouldwakeup)
 		toggle_ai(AI_ON)
 		return
 
-	var/virt_z = "[virtual_z()]"
-	if(!virt_z)
-		return
-	var/players_on_virtual_z = LAZYACCESS(SSmobs.players_by_virtual_z, virt_z)
-	if(!length(players_on_virtual_z))
-		toggle_ai(AI_Z_OFF)
-	else if(AIStatus == AI_Z_OFF)
-		toggle_ai(AI_ON)
+	var/virt_z = virtual_z()
+	var/players_on_virtual_z = 0
+	if(virt_z)
+		players_on_virtual_z = LAZYACCESS(SSmobs.players_by_virtual_z, "[virt_z]")
+		if(!length(players_on_virtual_z))
+			toggle_ai(AI_Z_OFF)
+		else if(AIStatus == AI_Z_OFF)
+			toggle_ai(AI_ON)
 
 /mob/living/simple_animal/adjustHealth(amount, updating_health = TRUE, forced = FALSE)
 	. = ..()
@@ -665,6 +664,7 @@
 	. = ..()
 	if(previous_virtual_z)
 		LAZYREMOVEASSOC(SSidlenpcpool.idle_mobs_by_virtual_level, "[previous_virtual_z]", src)
-	toggle_ai(initial(AIStatus))
+	if(QDELETED(src))
+		return
 	if(new_virtual_z)
 		check_should_sleep()

code/modules/reagents/chemistry/reagents/trickwine_reagents.dm

@@ -30,7 +30,7 @@
 		if(!iscarbon(M))
 			var/mob/living/simple_animal/hostile/hostile_target = M
 			var/hostile_ai_status = hostile_target.AIStatus
-			hostile_target.AIStatus = AI_OFF
+			hostile_target.toggle_ai(AI_OFF)
 			addtimer(VARSET_CALLBACK(hostile_target, AIStatus, hostile_ai_status),reac_volume)
 		M.Jitter(3 * reac_volume)
 		M.Dizzy(2 * reac_volume)